Electric Power From The Sun

From time to time we hear of new schemes devised by inventors for
harnessing the tremendous energy shot earthward every minute of our lives
by "Old Sol". An American scientist, Mr. Henry F. Wi1lsie, has recently
proposed a new form of Solar Power Plant. Which comprises a number of
very interesting and radical features which would seem to promise a
successful future for it. Not only is Mr. Willsie a scientific
theoretician, but also a man of practical deeds, and to this end he
built, some years ago, a solar light and power plant on a small scale out
in Arizona.

The development of this plant nearly caused Mr. Willsie and his wife
their lives during their mane exciting adventures while experimenting in
the wilds and barrenness of an Arizona desert, where sandstorms,
cloudbursts, thirst and poisonous reptiles all combined to threaten their
very existence. All these experiences are interestingly told in an
absorbing novel written by Mrs. Honorť Willsie, entitled "The Forbidden
Trail."

Coming back once more to the scientific side of Mr. Willsieís interesting
invention, which is shown in the accompanying illustration in one of its
applications, we learn that the underlying principle is the drawing of
the heat from the sunís rays into a moving sheet of water, which passes
up and down thru a series of zigzag passageways, under a double thickness
of glass.

Where the sun has considerable thermal power, particularly in the
southern part of the United States and other more tropical parts of the
world. experience has shown that the sunís heat will cause the
temperature of the water to increase to about 150 degrees. The heated
water passes into a sulfur dioxid boiler, and eventually this water
returns to the glass heating tanks or planes exposed to the sunís rays.

Where a large plant of this type is properly laid out, the mirrors or
glass-covered tanks in which the water or liquid is heated by the sunís
rays may be arranged in a fixt position, or also they may be designed so
as to swing from east to west with the sun, so as to keep the rays
perpendicular to the surface at all hours of the day.

A year or so ago there was described in this journal another solar power
plant and an elaborate scheme was detailed and illustrated therein for
revolving glass heating units in perfect synchronism with the sun by
means of an electric-clock regulating device, so that not only did the
complete bank of solar units rotate from east to west, but also the angle
of the surface of the units was tilted so that this surface was kept
exactly at right angles with the solar rays, which means that the surface
of the glass tank or units must swing from right to left in the course of
the daylight period from eight to ten hours, and also they must be tilted
from a nearly vertical position in the morning - thence to a horizontal
position at noon - and then once more to an approximately vertical
position again in the evening.

In Mr. Willsieís solar power plant there is a trough arranged at the
bottom of the glass heating tank into which the heated water at a
temperature of 150 degrees or more runs off thru a pipe into the storage
tank which in insulated with layers of dry sand. Mr. Willsie explains
that the water will remain hot from four to ten days when stored in this
tank, and here we have the key to a very novel principle involved in Mr.
Willsieís plant, viz., that he can run his engine and dynamo at night
without any storage batteries and obtain electric lights, etc., which he
actually did at his Arizona plant.

Originally, however, when the plant is put into complete operation, the
heated water runs from these storage tanks into the sulfur dioxid engine
and boiler system, as shown clearly in the diagrammatical illustration
herewith. Sulfur dioxid, as is well known, has a low boiling point, so
that it can be placed in the boiler and heated up, allowing the hot water
to come into contact with the boiler tubes containing the sulfur dioxid.
When the sulfur dioxid in the boiler commences to boil, you then obtain
the necessary sulfur dioxid steam wherewith to run the engine. In other
words, instead of using the fire to make steam in the boiler, hot water
is used instead, which originally obtained its heat from the sun
directly.

As the sulfur dioxid steam leaves the engine cylinder it is not exhausted
into the open air, owing to its initial high cost, but it is exhausted
into a series of pipes over which cold water is sprayed. This water, in
the case of irrigation plants, such as that developed by Mr. Willsie in
Arizona, is the same water that is pumped by the engine (the pump being a
separate machine connected to the engine by belt or otherwise) for
irrigation purposes, so nothing is lost in this stage, but the sulfur
dioxid steam is condensed and is then re-pumped or otherwise directed
back again into the boiler, only to be heated all over again by the hot
water coming from the sun tanks.

As Mr. Willsie has pointed out, electric light was had at night at his
Arizona solar plant, which was actually made by the rays of the sun
shining during the preceding day, a seeming paradox, were it not for the
facts explained heretofore - that he has found it possible to cause the
hot water to retain its quota of heat energy even for several days at a
time, when it is stored in properly built tanks insulated with layers of
dry sand, or other heat insulating materials.

Where this may not be practicable, we can always have recourse to
electric storage batteries, in which the dynamo would pump electric
energy during the day on certain days. Then whenever the battery became
sufficiently low in its charge, the electric energy required could be
drawn from the storage battery at night or at any other time. Under
certain conditions it would probably not be necessary to operate the
solar plant to charge the storage battery more than one day a week, as,
for instance, where such a plant was installed (of the proper size, of
course) for, let us say, lighting a private dwelling or farmhouse and
outbuildings, etc. By having a sufficiently large storage battery which
would generate the energy required for lighting purposes for a period of
one week, this could be taken care of by charging for just one day
complete.

At any rate, it is a case of getting something for nothing, so far as
spending the "coin of the realm" is concerned, and this is what most
people are worried about today, with the H. C. L. still soaring skyward.
Of course, it is not something for nothing in a strict sense of the word,
for we are utilizing the energy of the sunís rays. The foregoing covers
the doubt exprest by many people when they first hear about solar energy
plants, for their invariable and natural first question is "What about
cloudy weather, and, even tho we have quite a number of sunny days, you
may even have three or four cloudy days in one week?" This is very true,
but the aforementioned explanation as to charging the storage batteries
but one or two days a week, or possibly, as Mr. Willsie points out, by
suitably storing the heated water in special storage tanks, explains this
problem.

And, anyway, it will probably not come to pass very soon that we shall be
selling and installing solar electric lighting plants on the roofs of
apartment houses, in the northern parts of the United States, as if these
were as cheap as sand in the Sahara Desert, the average city dweller
would not bother with it, when he can spend $2.00 or so a month and have
the local electric lighting company supply all the "juice" he requires
without bothering his head about it.

But it is another question when we come to consider the vast stretches of
land such as those in the South and Southwestern parts of the United
States, where the fight for survival of plant life is seen to be
dependent upon the all-important quantity water. And here is where these
solar plants should and will find their ultimate goal and adoption in
large quantities, for it is uneconomical under any consideration, to
attempt on a large scale an irrigation of such large tracts of desert by
means of coal or oil driven plants, as these fuel commodities are
becoming more expensive each year.